The present invention relates to an apparatus for the coating of substrates with thin films in a vacuum chamber having a target to be atomized, located opposite the substrate in the vacuum chamber, with magnets for the creation of a magnetic tunnel in front of the target area to be atomized. An inlet is provided for introducing a process gas into the vacuum chamber. The apparatus further includes an anode insulated electrically with respect to the vacuum chamber, and a current-voltage supply to create a plasma in front of the target.
A device is known for the carrying out of vacuum-technique processes in magnetic field-reinforced electrical discharges consisting of a magnet field-producing device and a target with a negative potential and an anode, between which the electrical discharge burns, see DD 123 952. In that device, the magnetic field-producing device with its pole shoes is shaped annularly and concentrically to the cathode and in accordance with the vacuum-technique process to be carried out, is located in the interior of the tubular target or around the outside. This arrangement produces inhomogeneous, torus-shaped magnetic fields, limited in the axis direction, whose main field direction in the area of the target is directed parallel to its axis direction. The anode surrounds the target tubularly with the placement of the magnetic field-producing device in the target, and when placed around the target, is situated in it as a tube or full material, wherein the magnetic field-producing device, the tubular target, and the anode can move relative to one another.
Also known is a device for high-rate atomizing according to the plasmatron principle; see DD 217 964 A3. This device includes a magnetic field-producing device with an annular slot, a cooled tubular target, and an anode, wherein, the magnetic-producing device has a longitudinally extended annular slot, which is, in fact, closed, in which the target is located in such a manner that its large axis runs parallel to the target axis. The anode surrounds the target in such a manner that the annular slot area is free, and by means of an adjusting device, the distance between the anode and the target surface can be adjusted to a fixed value. To produce a relative movement around the large axis, a drive is situated between the target and the magnetic field-producing device, and a device to change the distance between it and the target is located on the magnetic field-producing device.
Still further, from EP 0461 035 B1 is known a cathode for vacuum atomizing comprising a hollow body, essentially in the form of a rotary body, which can rotate around its axis, with a side wall, which extends along the axis, and two front sides, essentially vertical to the axis, wherein the hollow body is formed from material to be atomized, at least on the exterior of its side wall. There is a magnetic circuit for the magnetic enclosure, which is provided close to a target, and poles, parts made of magnetic-permeable metal and magnetizing agents, which are suitable for the production of a magnetic flux in the magnetic circuit. Included is a device for connection with a cooling circuit for the circulation of a cooling liquid in the hollow body, and a device for connection with an electric supply circuit. A driving device serves to rotate the hollow body around an axis, wherein the magnetic circuit extends peripherally with reference to the hollow body. The magnetizing agent is provided outside the body; and the poles of the magnetic circuit are provided along two generatrices of this hollow body, and an arc of the side wall for the hollow body, which is located between these two generatrices, forms the target of the cathode.
Finally, a device for the atomization of thin films of a selected coating material on essentially planar substrates has already been proposed (EP 0 070 899 B1), consisting of an evacuatable coating chamber, and a cathode affixed horizontally in this coating chamber, with an elongated, cylindrical tube element, on whose exterior surface, a layer of the coating material to be atomized is applied. Magnetic agents are placed in this tube element so as to provide an atomizing zone extending from it in the longitudinal direction. Devices to rotate this tube element around its longitudinal axis are provided, so as to bring various parts of the coating material into an atomizing position opposite the aforementioned magnetic agents and within the aforementioned atomizing zone and with agents located in the coating chamber for the horizontal support of substrates and for their transportation past the magnetic agents, so that they receive substrates of the atomized material.
An object of the invention is to create a device of the type described above, which ensures a particularly high target utilization and simultaneously, makes possible a high coating rate, so as to be able to coat individual substrates at a high throughput.